Nikon D3X vs Sony A99

The Nikon D3X and the Sony Alpha SLT-A99 are two professional cameras that were revealed to the public, respectively, in December 2008 and September 2012. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with a full frame sensor. The Nikon has a resolution of 24.4 megapixels, whereas the Sony provides 24 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Nikon D3X		Sony A99
Digital single lens reflex		Digital single lens reflex
Nikon F mount lenses		Sony A mount lenses
24.4 MP – Full Frame sensor		24 MP – Full Frame sensor
no Video		1080/60p Video
ISO 100-1,600 (50 - 6,400)		ISO 100-25,600
Optical viewfinder		Electronic viewfinder (2359k dots)
3.0" LCD – 922k dots		3.0" LCD – 1229k dots
Fixed screen (not touch-sensitive)		Fully flexible screen (no touchscreen)
5 shutter flaps per second		6 shutter flaps per second
Lens stabilization only		In-body stabilization
Weathersealed body		Weathersealed body
4400 shots per battery charge		500 shots per battery charge
160 x 157 x 88 mm, 1260 g		147 x 111 x 78 mm, 812 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D3X and the Sony Alpha SLT-A99? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.

Body comparison

The physical size and weight of the Nikon D3X and the Sony A99 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A99 is considerably smaller (35 percent) than the Nikon D3X. Moreover, the A99 is substantially lighter (36 percent) than the D3X. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.

The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the D3X gets 4400 shots out of its Nikon EN-EL4a battery, while the A99 can take 500 images on a single charge of its Sony NP-FM500H power pack. As can be seen in the images above, the D3X has a battery grip built in. This facilitates image-taking in portrait orientation and gives it additional battery power. In order to provide similar functionality for the A99, Sony provides the VG-C99AM vertical grip as an optional accessory (see here on ebay).

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.

Body Specifications

#		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Nikon D3X	160 mm	157 mm	88 mm	1260 g	4400	Y	Dec 2008	7,999	ebay.com
2.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
3.		Canon 1Ds Mark III	150 mm	160 mm	80 mm	1385 g	1800	Y	Aug 2007	7,999	ebay.com
4.		Nikon D6	160 mm	163 mm	92 mm	1270 g	3580	Y	Feb 2020	6,499	amazon.com
5.		Nikon D5	160 mm	159 mm	92 mm	1415 g	3780	Y	Jan 2016	6,499	ebay.com
6.		Nikon D4S	160 mm	157 mm	91 mm	1350 g	3020	Y	Feb 2014	6,499	ebay.com
7.		Nikon D750	141 mm	113 mm	78 mm	750 g	1230	Y	Sep 2014	2,299	ebay.com
8.		Nikon D4	160 mm	157 mm	91 mm	1340 g	2600	Y	Jan 2012	5,999	ebay.com
9.		Nikon D600	141 mm	113 mm	82 mm	850 g	900	Y	Sep 2012	2,099	ebay.com
10.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
11.		Nikon D700	147 mm	123 mm	77 mm	1074 g	1000	Y	Jul 2008	2,999	ebay.com
12.		Nikon D3	160 mm	157 mm	88 mm	1300 g	4300	Y	Aug 2007	4,999	ebay.com
13.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	4,499	amazon.com
14.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	3,199	ebay.com
15.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
16.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	1,999	ebay.com
17.		Sony A900	156 mm	117 mm	82 mm	895 g	880	Y	Sep 2008	2,999	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A99 was launched at a markedly lower price (by 65 percent) than the D3X, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A99 is 1 percent smaller. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 24.4MP, the D3X offers a slightly higher resolution than the A99 (24MP), but the D3X has marginally smaller individual pixels (pixel pitch of 5.94μm versus 5.96μm for the A99). Moreover, the A99 is a much more recent model (by 3 years and 9 months) than the D3X, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels.

The Nikon D3X has a native sensitivity range from ISO 100 to ISO 1600, which can be extended to ISO 50-6400. The corresponding ISO settings for the Sony Alpha SLT-A99 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-25600.

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). The Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics

#		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Nikon D3X	Full Frame	24.4	6048	4032	none	24.7	13.7	1992	88
2.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
3.		Canon 1Ds Mark III	Full Frame	21.0	5616	3744	none	24.0	12.0	1663	80
4.		Nikon D6	Full Frame	20.7	5568	3712	4K/30p	25.3	14.3	2886	95
5.		Nikon D5	Full Frame	20.7	5588	3712	4K/30p	25.1	12.3	2343	88
6.		Nikon D4S	Full Frame	16.2	4928	3280	1080/60p	24.4	13.3	3074	89
7.		Nikon D750	Full Frame	24.2	6016	4016	1080/60p	24.8	14.5	2956	93
8.		Nikon D4	Full Frame	16.2	4928	3280	1080/30p	24.7	13.1	2965	89
9.		Nikon D600	Full Frame	24.2	6016	4016	1080/30p	25.1	14.2	2980	94
10.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
11.		Nikon D700	Full Frame	12.1	4256	2832	none	23.5	12.2	2303	80
12.		Nikon D3	Full Frame	12.1	4256	2832	none	23.5	12.2	2290	81
13.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
14.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
15.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
16.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	79
17.		Sony A900	Full Frame	24.4	6048	4032	none	23.7	12.3	1431	79
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras are not only capable of taking still images, but can also record movies. The A99 indeed provides for movie recording, while the D3X does not. The highest resolution format that the A99 can use is 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A99 has an electronic viewfinder (2359k dots), while the D3X has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the A99 has a higher magnification than the one of the D3X (0.71x vs 0.70x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Nikon D3X and Sony A99 along with similar information for a selection of comparators.

Core Features

#		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Nikon D3X	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	n
2.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
3.		Canon 1Ds Mark III	optical	Y	3.0 / 230	fixed	n	1/8000s	5.0/s	n	n
4.		Nikon D6	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
5.		Nikon D5	optical	Y	3.2 / 2359	fixed	Y	1/8000s	14.0/s	n	n
6.		Nikon D4S	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
7.		Nikon D750	optical	Y	3.2 / 1229	tilting	n	1/4000s	6.0/s	Y	n
8.		Nikon D4	optical	Y	3.2 / 921	fixed	n	1/8000s	11.0/s	n	n
9.		Nikon D600	optical	Y	3.0 / 921	fixed	n	1/4000s	5.5/s	Y	n
10.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
11.		Nikon D700	optical	Y	3.0 / 922	fixed	n	1/8000s	8.0/s	Y	n
12.		Nikon D3	optical	Y	3.0 / 922	fixed	n	1/8000s	11.0/s	n	n
13.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
14.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
15.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
16.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/s	n	Y
17.		Sony A900	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the A99 and the D3X is in-body image stabilization (IBIS). The A99 reduces the risk of handshake-induced blur with all attached lenses, while the D3X offers no blur reduction with lenses that themselves do not provide optical image stabilization.

The Nikon D3X has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.

The D3X writes its imaging data to Compact Flash cards, while the A99 uses SDXC or Memory Stick PRO Duo cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.

Connectivity comparison

For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Nikon D3X and Sony Alpha SLT-A99 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

#		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Nikon D3X	Y	- / -	-	-	mini	2.0	-	-	-
2.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
3.		Canon 1Ds Mark III	Y	mono / -	-	-	-	2.0	-	-	-
4.		Nikon D6	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
5.		Nikon D5	Y	stereo / mono	Y	Y	mini	3.0	-	-	-
6.		Nikon D4S	Y	mono / mono	Y	Y	mini	2.0	-	-	-
7.		Nikon D750	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
8.		Nikon D4	Y	mono / mono	Y	Y	micro	2.0	-	-	-
9.		Nikon D600	Y	mono / mono	Y	Y	mini	2.0	-	-	-
10.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
11.		Nikon D700	Y	- / -	-	-	mini	2.0	-	-	-
12.		Nikon D3	Y	- / -	-	-	mini	2.0	-	-	-
13.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
14.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
15.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-
17.		Sony A900	Y	- / -	-	-	mini	2.0	-	-	-

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Travel and landscape photographers will find it useful that the A99 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the D3X and the A99 have been discontinued, but can regularly be found used on ebay. The A99 was replaced by the Sony A99, while the D3X does not have a direct successor. Further information on the features and operation of the D3X and A99 can be found, respectively, in the Nikon D3X Manual (free pdf) or the online Sony A99 Manual.

Review summary

So how do things add up? Is there a clear favorite between the Nikon D3X and the Sony A99? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Arguments in favor of the Nikon D3X:

• Better low-light sensitivity: Requires less light for good images (0.4 stops ISO advantage).
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More portrait friendly: Features an integrated vertical grip for easier portrait shooting.
• Longer lasting: Can take more shots (4400 versus 500) on a single battery charge.
• More heavily discounted: Has been available for much longer (launched in December 2008).

Advantages of the Sony Alpha SLT-A99:

• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• More framing info: Has an electronic viewfinder that displays shooting data.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.70x).
• More detailed LCD: Has a higher resolution rear screen (1229k vs 922k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (6 vs 5 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (147x111mm vs 160x157mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 448g or 36 percent) and is thus easier to take along.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• More affordable: Was introduced into a lower priced category (65 percent cheaper at launch).
• More modern: Reflects 3 years and 9 months of technical progress since the D3X launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A99 is the clear winner of the contest (13 : 6 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro shooter. Hence, the decision which camera is best and worth buying is often a very personal one.

How about other alternatives? Do the specifications of the Nikon D3X and the Sony A99 place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing whether the two cameras rank among the cream of the crop.

In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains incomplete and does no justice, for example, to the way the D3X or the A99 perform in practice. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.

Expert reviews

This is why hands-on reviews by experts are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.

Expert Camera Reviews

#		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Nikon D3X	..	..	..	86/100	4/5	5/5	Dec 2008	7,999	ebay.com
2.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
3.		Canon 1Ds Mark III	..	..	..	+ +	4.5/5	..	Aug 2007	7,999	ebay.com
4.		Nikon D6	..	..	4/5	..	4.5/5	4.5/5	Feb 2020	6,499	amazon.com
5.		Nikon D5	..	..	4/5	89/100	4.5/5	5/5	Jan 2016	6,499	ebay.com
6.		Nikon D4S	5/5	..	..	..	4.5/5	4.5/5	Feb 2014	6,499	ebay.com
7.		Nikon D750	5/5	+ +	4/5	90/100	4.5/5	4.5/5	Sep 2014	2,299	ebay.com
8.		Nikon D4	..	..	..	..	4.5/5	4.5/5	Jan 2012	5,999	ebay.com
9.		Nikon D600	4/5	+ +	..	87/100	5/5	4.5/5	Sep 2012	2,099	ebay.com
10.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
11.		Nikon D700	..	89/100	..	+ +	4.5/5	4.5/5	Jul 2008	2,999	ebay.com
12.		Nikon D3	..	..	..	+ +	5/5	4.5/5	Aug 2007	4,999	ebay.com
13.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	4,499	amazon.com
14.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	3,199	ebay.com
15.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
16.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	1,999	ebay.com
17.		Sony A900	..	+ +	..	+ +	4.5/5	5/5	Sep 2008	2,999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Check A99 offers at
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Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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